Roller shade with a pretensioned spring and method for pretensioning the spring

摘要

A roller shade is disclosed having a counterbalancing assembly with an optimally pretensioned spring that lowers the torque load on the motor of the roller shade throughout the rolling up or rolling down cycles. The roller shade comprises a roller tube, a gudgeon pin having a first stop, a gudgeon body having a through bore and rotatably connected about the gudgeon pin and operably connected to the roller tube, a limit nut operably connected to the gudgeon body and adapted to axially travel along the gudgeon pin within the through bore, a spring, a first spring carrier connected to the first end of the spring and operably connected to the gudgeon pin, and a second spring carrier connected to the second end of the spring and operably connected to the roller tube. The spring is pretensioned and the limit nut abuts the first stop thereby locking the pretension. Rotation of the roller tube to roll down the shade further tensions the spring, and rotation of the roller tube to roll up the shade releases the tension in the spring.

主权项

1. A roller shade comprising:
a roller tube; a gudgeon pin comprising a first stop and a second stop; a gudgeon body rotatably connected about the gudgeon pin and operably connected to the roller tube, wherein the gudgeon body comprises a through bore; a limit nut operably connected to the gudgeon body and adapted to axially travel along the gudgeon pin, within the through bore and between the first stop and the second stop; a pretensioned spring comprising a first end and a second end and the spring longitudinally extending therebetween, wherein the limit nut abuts the first stop or the second stop thereby locking pretension in the pretensioned spring; a first spring carrier connected to the first end of the spring and operably connected to the gudgeon pin; and a second spring carrier connected to the second end of the spring and operably connected to the roller tube; wherein during pretensioning of the pretensioned spring, the roller shade comprises:
the second spring carrier positioned within the roller tube such that the second spring carrier is operably connected to the roller tube;the gudgeon body positioned outside the roller tube;the gudgeon body rotating with respect to the roller tube, thereby causing the limit nut to rotate and axially travel in a first direction, until the limit nut comes in contact with the first stop or the second stop;after the limit nut comes in contact with the first stop or the second stop, the gudgeon body further rotating with respect to the roller tube a predetermined number of pretension turns, thereby causing the first spring carrier and the first end of the spring to rotate with respect to the second spring carrier and the second end of the spring; andthe gudgeon body inserted inside the roller tube thereby locking the pretension.